The neuronal ceroid lipofuscinoses (NCLs, Batten disease) are devastating inherited fatal neurodegenerative diseases of children. At present there are no effective therapies and palliative care is difficult. Studies on a CLN6 form in New Zealand sheep have proved invaluable in understanding the biochemistry and preclinical pathology. These sheep have a human-like brain anatomy, physiology and genetic organization, and display similar neuropathology dominated by cortical atrophy, and a similar development of clinical disease. The overall aim of this project is to complete understanding to a point where in vivo trials of viral vector gene therapies can begin. Molecular biology, biochemistry and immunohistological experiments will define the gene product required for correction and its subcellular site of residence. Neuron cultures will be be tested with lenti- and adeno-associated virally derived vectors to determine suitability for transduction of the gene into sheep neurons and glial cells. Prenatal and preclinical neuropathology studies indicated that glial activation has a primary role in the pathogenesis of this disease. Further studies will define the cascade of glial cell activation and inflammation, to determine the critical steps and thus determine the most effective point for intervention. The effectiveness of chronic treatment with anti-inflammatory drugs on the development of the disease in sheep will be tested in vivo. Prolonged neurogenesis and migration of cells from the subventricular zone to the affected areas in the brains of affected sheep was also indicated in the pathology studies. The extent of this will be established by BrdU labeling of new cells in vivo and antibody detection. Finally the usefulness of this migration for carrying a gene in viral vectors to the areas where it is required will be determined by targeted injection of the preferred vector carrying a reporter gene into affected sheep brains and detection of the dispersal of gene expression. These studies are aimed at providing all the requirements for directly testing gene therapy on the sheep, in combination with suppression of inflammation. The target cells will have been identified along with the CLN6 gene product relevant to them. The time window for therapy will have been defined along with the role of suppression of inflammation in slowing the course of the disease. The most effective viral vector will have been identified and the techniques for injection into the SVZ established. REVELANCE: This project intends to gain knowledge to define realistic therapies in a large animal form of Batten disease that can be tested for possible human use. Much of the knowledge gained will be relevant to other diseases and other treatment strategies, such as Alzheimer's disease and stem cell transplantation.